NBN EN 16397-1:2014

This European Standard specifies the performance requirements for flexible couplings and adaptors and bushes for use with pipes and fittings in drain and sewer systems, usually operated under gravity and periodic hydraulic surcharge, both above and below ground inside or outside buildings and intended to connect pipes for:
- repair of damaged pipelines;
- connecting pipes of different materials and/or diameters;
- jointing short/cut lengths of pipe;
- jointing specific pipe systems;
- jointing post-inserted preformed junctions.
Typically a coupling consists of a moulded or extruded flexible sleeve with two clamping bands with or without a shear band. The clamping bands enable the sleeve to form a seal with the pipes to be jointed. The shear band gives resistance to shear forces. Connections may be made between pipes which cannot be satisfactorily jointed by a coupling alone, of dissimilar sizes or material, by using an appropriate bush or bushes with the coupling or by using an appropriate adaptor.